Roof Cover Impact on Cooling Energy Use of Office Buildings

2014 ◽  
Author(s):  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Calculation Model ◽  
Office Building ◽  
Climate Zones ◽  
Building Energy Use ◽  
Detailed Simulation ◽  
Simplified Calculation ◽  
The Impact

This paper analyzes the impact of roof covers on office building energy use for representative US climate zones. In particular, the study presented in the paper investigates the potential annual cooling energy use savings that roof covers could provide using whole-building simulation analysis to evaluate the performance of a 2-story office building in five US locations. Three parameters of the roof covers including their size, height, and transmittance, are considered in the analysis. The simulation results indicate that while roof covers had similar affects on buildings in all climate zones, their impact in reducing cooling energy usage is different and is more pronounced in cooler climates. Specifically, roof covers could potentially achieve cooling energy savings of up to: 25% in Houston, 33% in Atlanta, 31% in Nashville, 38% in Chicago, and 41% in Madison. Based on the detailed simulation analysis results, a simplified calculation model is developed to help the estimation of cooling energy savings as a function of the roof cover size, height, and transmittance.

Analysis of Electrical Energy Savings From Daylighting Through Skylights

Solar Energy ◽  
2005 ◽  
Author(s):  
Abdelkarim Nemri ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Control Strategies ◽  
Electrical Energy ◽  
Office Building ◽  
Analysis Tool ◽  
Energy Saving Potential ◽  
Lighting Energy ◽  
The Impact

This paper provides a simplified analysis tool to assess the energy saving potential of daylighting for commercial buildings through skylights. Specifically, the impact of daylighting is investigated for various fenestration opening sizes, glazing types, control strategies, and geographic locations. A top floor of a prototypical office building has been considered in the analysis. The results obtained for the office building can be applied to other types of buildings such as retails stores, schools, and warehouses. Based on the simulation analysis results, it was determined that skylight to floor ratio more than 0.3 does not affect significantly the lighting energy savings. An optimum value of skylight to floor area ratio was found to be 0.2 to minimize the annual total building energy use.

Residential Energy Analysis: Regression Analysis of Heating Degree Days With Temperature Setback for Selected ASHRAE Climate Zones

2011 ◽  
Author(s):  
Patrick A. Kearns ◽  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Simulation Analysis ◽  
Residential Buildings ◽  
Base Temperature ◽  
Degree Days ◽  
Climate Zones ◽  
Detailed Simulation ◽  
Input Variables ◽  
Heating Degree Days ◽  
The Impact

Heating Degree Days (HDDs), calculated from hourly weather data, are often used to estimate energy savings for a variety of energy efficiency measures (EEMs) to be applied to conditioned spaces in buildings. More specifically, application of HDDs is useful for estimating savings from weather-dependent EEMs. For first order estimation, it is often problematic to calculate HDDs for a given base temperature, when temperature setbacks are used in the conditioned spaces. This paper provides a set of correlations to characterize HDDs for selected ASHRAE Climate Zones as functions of three key parameters including the base temperature, setback temperature level (delta-T), and setback duration. In addition to the well-documented pattern of decreasing HDDs for decreasing base temperature, it was also shown that HDDs are inversely proportional to both setback duration and temperature setback differential levels. In the analysis presented in this paper, corrections to estimate HDDs when temperature setbacks are used for typical residential space heating schedules during unoccupied periods which occurred from 8 am to 5 pm Monday through Friday. In particular, regression correlations using two- and three-parameter models have been developed to estimate HDDs for multiple US locations that account for the impact of temperature setbacks on the heating requirements of residential buildings. For the two-parameter model, the input variables for the regression correlations are setback hours and delta T; for the three-parameter model, the input variables for the correlations include setback hours, delta T, and base temperature. The prediction accuracy for the energy savings, due to a set of EEMs, obtained from the HDD method —using the developed correlations— is tested against whole-building detailed energy simulation analysis for two single family homes. Detailed energy audits including utility data analysis have been carried out for both homes to calibrate the detailed simulation model and evaluate the effectiveness of the EEMs in reducing building energy use. The results from the detailed simulation analysis are then compared to those obtained from the HDD with temperature setbacks.

scholarly journals Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

2021 ◽  
Vol 13 (4) ◽  
pp. 1595
Author(s):  
Valeria Todeschi ◽  
Roberto Boghetti ◽  
Jérôme H. Kämpf ◽  
Guglielmina Mutani
Keyword(s):  
Machine Learning ◽  
Energy Use ◽  
Residential Buildings ◽  
Building Energy ◽  
Energy Performance ◽  
Space Heating ◽  
Engineering Model ◽  
Building Energy Use ◽  
The Impact ◽  
The City

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

People or Systems: Does Productivity Enhancement Matter More than Energy Management in LEED Certified Buildings?

2021 ◽  
Vol 13 (24) ◽  
pp. 13863
Author(s):  
Yana Akhtyrska ◽  
Franz Fuerst
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Energy Use ◽  
Management Practices ◽  
Energy Savings ◽  
Occupant Comfort ◽  
Energy Use Intensity ◽  
Using Data ◽  
Advanced Metering ◽  
The Impact

This study examines the impact of energy management and productivity-enhancing measures, implemented as part of LEED Existing Buildings Operations and Management (EBOM) certification, on source energy use intensity and rental premiums of office spaces using data on four major US markets. Energy management practices, comprised of commissioning and advanced metering, may reduce energy usage. Conversely, improving air quality and occupant comfort in an effort to increase worker productivity may in turn lead to higher overall energy consumption. The willingness to pay for these features in rental office buildings is hypothesised to depend not only on the extent to which productivity gains enhance the profits of a commercial tenant but also on the lease arrangements for passing any energy savings to the tenant. We apply a difference-in-differences method at a LEED EBOM certification group level and a multi-level modelling approach with a panel data structure. The results indicate that energy management and indoor environment practices have the expected effect on energy consumption as described above. However, the magnitude of the achieved rental premiums appears to be independent of the lease type.

Analysis of Daylighting Benefits for Office Buildings in Egypt

Solar Energy ◽  
2004 ◽  
Author(s):  
Mostafa Abd El Mohimen ◽  
George Hanna ◽  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Simulation Analysis ◽  
Window Size ◽  
Electrical Energy ◽  
Office Buildings ◽  
Wall Area ◽  
Electricity Use ◽  
Daylighting Control ◽  
The Impact ◽  
Geographical Locations

This paper summarizes the results of a simulation analysis to determine the effectiveness of daylighting in reducing electrical energy consumption for office buildings in Egypt. Specifically, the impact on daylighting performance is investigated of window size, building size, daylighting control, and glazing type for three geographical locations in Egypt. It was determined that a window to wall area ratio of 0.20 minimizes the total annual electricity use for office buildings in three Egyptian locations, Cairo, Alexandria, and Aswan. A simplified analysis method is developed based on the analysis results to estimate the annual electrical energy savings attributed to daylighting.

scholarly journals Design and Application of Cellular Concrete on a Mexican Residential Building and Its Influence on Energy Savings in Hot Climates: Projections to 2050

2020 ◽  
Vol 10 (22) ◽  
pp. 8225
Author(s):  
Ana C. Borbon-Almada ◽  
Jorge Lucero-Alvarez ◽  
Norma A. Rodriguez-Muñoz ◽  
Manuel Ramirez-Celaya ◽  
Samuel Castro-Brockman ◽  
...  
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Design Stage ◽  
Second Phase ◽  
Dynamic Simulations ◽  
Conventional Concrete ◽  
The Impact ◽  
Cellular Concrete

The thermal performance of economical housing located in hot climates remains a pending subject, especially in emerging economies. A cellular concrete mixture was designed, considering its thermophysical properties, to apply the new material into building envelopes. The proposed materials have low density and thermal conductivity to be used as a nonstructural lightweight construction element. From the design stage, a series of wall systems based on cellular concrete was proposed. Whereas in the second phase, the materials were analyzed to obtain the potential energy savings using dynamic simulations. It is foreseen that the energy consumption in buildings located in these climates will continue to increase critically due to the temperature increase associated with climate change. The temperatures predicted mean vote (PMV), electric energy consumption, and CO2 emissions were calculated for three IPCC scenarios. These results will help to identify the impact of climate change on the energy use of the houses built under these weather conditions. The results show that if the conventional concrete blocks continue to be used, the air conditioning energy requirements will increase to 49% for 2030 and 61% by 2050. The proposed cellular concrete could reduce energy consumption between 15% and 28%, and these saving rates would remain in the future. The results indicate that it is necessary to drive the adoption of lightweight materials, so the impact of energy use on climate change can be reduced.

scholarly journals Simulation analysis of Macro-Packed Phase Change Materials (MPPCM) to reduce building energy use

2019 ◽  
Vol 609 ◽  
pp. 042058
Author(s):  
Beom Yeol Yun ◽  
Sungwoong Yang ◽  
Ji Hun Park ◽  
Jongki Lee ◽  
Seunghwan Wi ◽  
...  
Keyword(s):  
Phase Change ◽  
Energy Use ◽  
Phase Change Materials ◽  
Simulation Analysis ◽  
Building Energy ◽  
Building Energy Use

A methodology for estimating office building energy use baselines by means of land use legislation and reference buildings

2017 ◽  
Vol 143 ◽  
pp. 100-113 ◽  
Author(s):  
Tatiana Alves ◽  
Luiz Machado ◽  
Roberta Gonçalves de Souza ◽  
Pieter de Wilde
Keyword(s):  
Land Use ◽  
Energy Use ◽  
Building Energy ◽  
Office Building ◽  
Building Energy Use
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